Implement single window mode option in parallel to multi-window support

For debugging and development purposes it's sometimes useful to run the
full Android system in a single and statically sized window. This is not
going to be a widely used mode but can be helpful at times.

Also makes our window/layer management a bit more modular to allow easy
additions of new strategies/impementations.

Implement simple app database which maintains app information at runtime

This helps us to collect information about an app (title, ..) we can
reuse for certain other things like window construction.

Remove all debian packaging as its outdated and not used

Use a -dev suffix for our version as long as we're in development

Small fixes to get the app launchers working when running within a snap

Add simple command to print out various system information

F/use snap user common

Set XDG_DATA_HOME to SNAP_COMMON to have a common place for our app l…

Improve synchronization of application launchers between the host and Android

Rework logger integration with the emugl component a bit

Fetch correct dkms version from deban package in post install

Extend documentation with various additional details

Take version from changelog

Cleanup program termination so that things are correctly released